Synovial Cell Hyperplasia Research Articles

Role of Bioactive Compounds, Novel Drug Delivery Systems, and Polyherbal Formulations in the Management of Rheumatoid Arthritis.

Rheumatoid Arthritis (RA) is an autoimmune disorder that generally causes joint synovial inflammation as well as gradual cartilage and degenerative changes, resulting in progressive immobility. Cartilage destruction induces synovial inflammation, including synovial cell hyperplasia, increased synovial fluid, and synovial pane development. This phenomenon causes articular cartilage damage and joint alkalosis. Traditional medicinal system exerts their effect through several cellular mechanisms, including inhibition of inflammatory mediators, oxidative stress suppression, cartilage degradation inhibition, increasing antioxidants and decreasing rheumatic biomarkers. The medicinal plants have yielded a variety of active constituents from various chemical categories, including alkaloids, triterpenoids, steroids, glycosides, volatile oils, flavonoids, lignans, coumarins, terpenes, sesquiterpene lactones, anthocyanins, and anthraquinones. This review sheds light on the utilization of medicinal plants in the treatment of RA. It explains various phytoconstituents present in medicinal plants and their mechanism of action against RA. It also briefs about the uses of polyherbal formulations (PHF), which are currently in the market and the toxicity associated with the use of medicinal plants and PHF, along with the limitations and research gaps in the field of PHF. This review paper is an attempt to understand various mechanistic approaches employed by several medicinal plants, their possible drug delivery systems and synergistic effects for curing RA with minimum side effects.

Carveol alleviates osteoarthritis progression by acting on synovial macrophage polarization transformation: An in vitro and in vivo study

Osteoarthritis (OA) is a heterogeneous disease that affects the entire joint. Its pathogenesis involves hypertrophy and hyperplasia of synovial cells and polarization infiltration of macrophages, in which macrophages, as a potential target, can delay the progression of the disease by improving the immune microenvironment in OA. To investigate the role and regulatory mechanism of Carveol in cartilage and synovial macrophage reprogramming and crosstalk during the development of OA. RAW264.7 mouse macrophage cell line was mainly used to stimulate macrophages to polarization towards M1 and M2 by LPS, IL4+IL13, respectively. Different concentrations of Carveol were given to intervene, and macrophage culture medium was collected to intervene mouse C57BL6J chondrocytes. ROS assay kit, western blotting, cellular immunofluorescence, scanning microscope and section histology were used to evaluate the effect of Carveol on anti-M1-polarization, M2-polarization promotion and cartilage protection. The mouse destabilization of medial meniscus (DMM) model was observed by micro-CT scan and histology. We found that CA could inhibit the increase of macrophage inflammation level under the intervention of LPS and promote the production of M2 anti-inflammatory substances under the intervention of IL-4+IL13. In addition, Carveol activated NRF2/HO-1/NQO1 pathway and enhanced ROS clearance in chondrocytes under the intervention of macrophage culture medium. The phosphorylation of I-κBα is inhibited, which further reduces the phosphorylation of P65 downstream of nuclear factor-κB (NF-κB) signaling pathway. In addition, Carveol inhibits mitogen activated protein kinase (MAPK) signaling molecules P-JNK, P-ERK and P–P38, and inhibits the production of inflammatory mediators. In vivo, Carveol can reduce osteophytes and bone spurs induced by DMM, reduce hypertrophy of synovial cells, reduce infiltration of macrophages, inhibit subchondral bone destruction, and reduce articular cartilage erosion. Our study suggests that synovial macrophages are potential targets for OA treatment, and Carveol is an effective candidate for OA treatment.

Excess Growth Hormone Triggers Inflammation-Associated Arthropathy, Subchondral Bone Loss, and Arthralgia

Growth hormone (GH) is a key mediator of skeletal growth. In humans, excess GH secretion due to pituitary adenoma, seen in patients with acromegaly, results in severe arthropathies. This study investigated the effects of long-term excess GH on the knee joint tissues. One year-old wild-type (WT) and bovine GH (bGH) transgenic mice were used as a model for excess GH. bGH mice showed increased sensitivity to mechanical and thermal stimuli, compared with WT mice. Micro-computed tomography analyses of the distal femur subchondral bone revealed significant reductions in trabecular thickness and significantly reduced bone mineral density of the tibial subchondral bone-plate associated with increased osteoclast activity in both male and female bGH compared with WT mice. bGH mice showed severe loss of matrix from the articular cartilage, osteophytosis, synovitis, and ectopic chondrogenesis. Articular cartilage loss in the bGH mice was associated with elevated markers of inflammation and chondrocyte hypertrophy. Finally, hyperplasia of synovial cells was associated with increased expression of Ki-67 and diminished p53 levels in the synovium of bGH mice. Unlike the low-grade inflammation seen in primary osteoarthritis, arthropathy caused by excess GH affects all joint tissues and triggers severe inflammatory response. Data from this study suggest that treatment of acromegalic arthropathy should involve inhibition of ectopic chondrogenesis and chondrocyte hypertrophy.

MicroRNAs and long non-coding RNAs in cartilage homeostasis and osteoarthritis.

During the last decade, osteoarthritis (OA) has become one of the most prevalent musculoskeletal diseases worldwide. OA is characterized by progressive loss of articular cartilage, abnormal remodeling of subchondral bone, hyperplasia of synovial cells, and growth of osteophytes, which lead to chronic pain and disability. The pathological mechanisms underlying OA initiation and progression are still poorly understood. Non-coding RNAs (ncRNAs) constitute a large portion of the transcriptome that do not encode proteins but function in numerous biological processes. Cumulating evidence has revealed a strong association between the changes in expression levels of ncRNA and the disease progression of OA. Moreover, loss- and gain-of-function studies utilizing transgenic animal models have demonstrated that ncRNAs exert vital functions in regulating cartilage homeostasis, degeneration, and regeneration, and changes in ncRNA expression can promote or decelerate the progression of OA through distinct molecular mechanisms. Recent studies highlighted the potential of ncRNAs to serve as diagnostic biomarkers, prognostic indicators, and therapeutic targets for OA. MiRNAs and lncRNAs are two major classes of ncRNAs that have been the most widely studied in cartilage tissues. In this review, we focused on miRNAs and lncRNAs and provided a comprehensive understanding of their functional roles as well as molecular mechanisms in cartilage homeostasis and OA pathogenesis.

Do Synovial Inflammation and Meniscal Degeneration Impact Clinical Outcomes of Patients Undergoing Arthroscopic Partial Meniscectomy? A Histological Study.

The menisci exert a prominent role in joint stabilization and in the distribution of mechanical loading. Meniscal damage is associated with increased risk of knee OA. The aim of this study was to characterize the synovial membrane and meniscal tissues in patients undergoing arthroscopic partial meniscectomy for meniscal tear and to evaluate association with clinical outcomes. A total of 109 patients were recruited. Demographic and clinical data were collected. Visual Analogic Scale (VAS) measuring pain and Knee injury and Osteoarthritis Outcome Score (KOOS) were recorded at baseline and at 2-years follow-up. Histological and immunohistochemical characterizations were performed on synovial membranes and meniscal tissues. More than half of the patients demonstrated synovial mononuclear cell infiltration and hyperplasia. Synovial fibrosis was present in most of the patients; marked vascularity and CD68 positivity were observed. Inflammation had an impact on both pain and knee symptoms. Patients with synovial inflammation had higher values of pre-operative VAS and inflammation. Higher pre-operative pain was observed in patients with meniscal MMP-13 production. In conclusion, multivariate analysis showed that synovial inflammation was associated with pre-operative total KOOS scores, knee symptoms, and pain. Moreover, meniscal MMP-13 expression was found to be associated with pre-operative pain in multivariate analysis. Thus, targeting inflammation of the synovial membrane and meniscus might reduce clinical symptoms and dysfunction at the time of surgery.

High-Molecular-Weight Hyaluronic Acid Inhibits IL-1β-Induced Synovial Inflammation and Macrophage Polarization through the GRP78-NF-κB Signaling Pathway.

Recent evidence has suggested that synovial inflammation and macrophage polarization were involved in the pathogenesis of osteoarthritis (OA). Additionally, high-molecular-weight hyaluronic acid (HMW-HA) was often used clinically to treat OA. GRP78, an endoplasmic reticulum (ER) stress chaperone, was suggested to contribute to the hyperplasia of synovial cells in OA. However, it was still unclear whether HMW-HA affected macrophage polarization through GRP78. Therefore, we aimed to identify the effect of HMW-HA in primary synovial cells and macrophage polarization and to investigate the role of GRP78 signaling. We used IL-1β to treat primary synoviocytes to mimic OA, and then treated them with HMW-HA. We also collected conditioned medium (CM) to culture THP-1 macrophages and examine the changes in the phenotype. IL-1β increased the expression of GRP78, NF-κB (p65 phosphorylation), IL-6, and PGE2 in primary synoviocytes, accompanied by an increased macrophage M1/M2 polarization. GRP78 knockdown significantly reversed the expression of IL-1β-induced GRP78-related downstream molecules and macrophage polarization. HMW-HA with GRP78 knockdown had additive effects in an IL-1β culture. Finally, the synovial fluid from OA patients revealed significantly decreased IL-6 and PGE2 levels after the HMW-HA treatment. Our study elucidated a new form of signal transduction for HMW-HA-mediated protection against synovial inflammation and macrophage polarization and highlighted the involvement of the GRP78-NF-κB signaling pathway.

Mechanism of oxymatrine in treatment of collagen-induced arthritis in mice

Sophorae Flavescentis Radix, the root of Sophora flavescens Ait., has been widely applied in the medical field due to its anti-inflammatory, analgesic, bacteriostatic, antiviral, antitumor, and other pharmacological effects. The present study investigated the anti-rheumatoid arthritis effect of oxymatrine(OMT), the active component of Sophorae Flavescentis Radix by observing its effect on the function of B lymphocytes in collagen-induced arthritis(CIA) mice through the Toll-like receptor 9(TLR9)/myeloid differentiation factor 88(MyD88)/signal transducer and activator of transcription 3(STAT3) pathway. The CIA model in DBA/1 J mice was induced by bovine type Ⅱ collagen and complete Freund's adjuvant(CFA). Fifteen days after the primary immunization, mice were treated with OMT for 30 days by intraperitoneal injection. Paw swelling and arthritis index(AI) score were evaluated every 3 days. Joint histopathologic changes were observed by HE staining. Magnetic-activated cell sorting(MACS) was used to isolate B lymphocytes from the spleen of CIA mice spleen. The serum expression level of interleukin(IL)-21 was examined by the enzyme-linked immunosorbent assay(ELISA). The expression of TLR9, STAT3, p-STAT3, and IL-21 in B lymphocytes was detected by Western blot. The mRNA expression of TLR9, STAT3, and IL-21 in B lymphocytes was detected by real-time fluorescence-based quantitative PCR(qRT-PCR). The results showed that OMT could significantly alleviate the paw swelling, decrease the AI score, relieve synovial inflammatory cell infiltration and hyperplasia, reduce the level of inflammatory cytokines, and inhibit the expression of TLR9, STAT3, p-STAT3, and IL-21 of B lymphocytes in CIA mice. Therefore, OMT may alleviate rheumatoid arthritis by regulating TLR9/MyD88/STAT3 pathway in B lymphocytes, providing a valuable reference for the application of OMT in the clinical treatment of rheumatoid arthritis.

Mycoplasma synoviae induces serum amyloid A upregulation and promotes chicken synovial fibroblast cell proliferation

Mycoplasma synoviae (MS) infection causes infectious synovitis and arthritis with hyperplasia of synovial cells in the chicken joint. However, its mechanism is unknown. We used primary chicken synovial fibroblast (CSF) as the research object to study the role of MS in the proliferation of MS-infected CSF and determine the mechanisms involved. Using integrated transcriptomic and proteomic analyses of the interaction between CSF and MS, we screened a proliferation-regulated factor, serum amyloid A (SAA), that may regulate proliferation of MS-infected CSF. SAA appears to be associated with MS-induced CSF proliferation. To study the role of SAA in MS-induced CSF proliferation, a eukaryotic expression vector overexpressing SAA and a small interfering RNA (siRNA) targeting Saa were constructed to manipulate the expression of SAA. Cell proliferation and apoptosis were detected via cell counting kit-8 (CCK-8), 5-Ethynyl-2′-deoxyuridine (EdU), or terminal deoxyribonucleotidyl transferase-mediated dUTP nick-dnd labeling (TUNEL) assays, respectively. Western blot analysis was used to examine the protein expression level of SAA, cyclin E1, and cyclin-dependent kinase 2 (CDK2). In vitro, MS significantly promoted the proliferation of CSF and increased the production of SAA. Overexpression of SAA accelerated the proliferative ability of CSF, whereas knockdown of SAA depressed the proliferative ability of CSF. A TUNEL assay indicated that MS did not induce apoptosis. Silencing of SAA suppressed the expression of cyclin E1 and CDK2. These results suggest that MS may upregulate the expression of SAA, accelerate the cell cycle, and promote proliferation of CSF.

Histone deacetylase 1 is increased in rheumatoid arthritis synovium and promotes synovial cell hyperplasia and synovial inflammation in the collagen-induced arthritis mouse model via the microRNA-124-dependent MARCKS-JAK/STAT axis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease featured by synovial joint inflammation. Increasing evidence has highlighted microRNAs (miRNAs) and histone deacetylase 1 (HDAC1) as active participants in RA progression. Hence, the present study aims to explore the functions of HDAC1 and miR-124 on synovial cell hyperplasia and synovial inflammation in RA. The expression of HDAC1, miR-124 and MARCKS was determined in the synovial tissues collected from 25 RA patients by RT-qPCR and Western blot analysis. Next, a mouse model with collagen-induced arthritis (CIA) was established, from which fibroblast-like synovial cells (FLSs) were isolated. Then the effect of HDAC1, miR-124 and MARCKS on synovial cell hyperplasia and synovial inflammation in CIA mice was evaluated by HE staining, ELISA, and EdU assays. Afterwards, the interaction among HDAC1, miR-124, MARCKS and the JAK/STAT signalling pathway was assessed by ChIP and dual luciferase reporter assay. Finally, the effect of HDAC1 on RA was further verified by establishing a CIA mouse model. HDAC1 was highly expressed and miR-124 and MARCKS were poorly expressed in synovial tissues of CIA. Silencing HDAC1 inhibited synovial cell hyperplasia and synovial inflammation by elevating MARCKS and miR-124 both in vitro and in vivo. Deficiency of HDAC1 promoted H3 and H4 acetylation of miR-124 and MARCKS promoter region. miR-124 alleviated synovial cell hyperplasia and synovial inflammation by repressing the JAK/STAT signalling pathway in CIA. To sum up, silencing HDAC1 mitigates synovial cell hyperplasia and synovial inflammation in mice with CIA by elevating miR-124 and MARCKS expression, thus highlighting a promising competitive new target for RA treatment.

Can NMR (Nuclear Magnetic Resonance) spectroscopy serve as a diagnostic tool for Rheumatoid Arthritis?

Rheumatoid arthritis (RA) is a general, chronic, systemic and autoimmune inflammatory disease. This disease represents the inflammatory response of the synovium resulting to hyperplasia of synovial cells along with associated destruction of cartilage, bone and ligaments, eventually leading to deformity of the joints. There is a considerable alteration observed in the metabolism. Chronic inflammation is responsible for altering the metabolism and also the metabolic profile of an individual patient with early inflammatory arthritis expects the following route of disease. These metabolic changes would identify biomarkers, which may be useful for the diagnostic purposes. NMR (nuclear magnetic resonance) spectroscopy based metabolomics studies of serum, urine and synovial fluid of RA were performed. These studies reflected the possibility of the development of metabolomics based diagnostic methods for RA. So, our question “Can NMR (Nuclear Magnetic Resonance) spectroscopy serve as a diagnostic tool for rheumatoid arthritis?” will definitely get an answer with the development of NMR based diagnostic method for RA.

Different synovial vasculogenic profiles of primary, rapidly destructive and osteonecrosis-induced hip osteoarthritis. An immunohistochemistry study.

To present a hypothesis regarding the pathways of angiogenesis in primary versus secondary hip osteoarthritis (OA). In synovial tissue samples provided by 57 consecutive patients who underwent hip arthroplasty, immunohistochemical examinations were performed using the following angiogenesis-related antibodies: VEGF-A, COX-2, maspin and the endothelial cells markers CD31 and CD105. The cases were divided into three categories: classic primary hip OA (group A; n = 16), rapidly destructive hip OA (group B; n = 24) and hip OA secondary to avascular osteonecrosis of the femoral head (group C; n = 17). The endothelial area (EA) was digitally quantified for both CD31 and CD105. The large mature vessels with CD105-positive activated endothelium predominated in group C, which also showed the highest CD105 median EA value (7.31 ± 4.01, compared to 4.76 ± 3.73 for group A and 6.69 ± 3.53 for group B). In groups A and B, synovial cell hyperplasia and the predominance of small immature vessels were characteristic. CD105, VEGF-A and COX-2 were focally seen in the synovial membrane, without maspin positivity. The severity of hip OA can be related to angiogenesis pathways that are not maspin-mediated. In primary hip OA, angiogenesis may be induced by a combined mechanism: hypoxia-related VEGF-dependent vasculogenesis and endothelial differentiation of the activated pluripotent cells, which are released from the hyperplastic synovial cells layer. An endothelial mesenchymal transition is assumed to be involved in the fibrotic process.

JOINT LESIONS IN TAIWAN NATIVE COLORED BROILER CHICKEN WITH NATURAL AND EXPERIMENTALSTAPHYLOCOCCUS AUREUSORS. COHNIIINFECTION

A total of 14 isolates of Staphylococcus aureus and 10 isolates of Staphylococcus cohnii subsp. urealyticum were isolated from 90 field cases of arthritis. Joint lesions that were induced by both staphylococci could not be distinguished and were characterized by fibrinopurulent arthritis and tenosynovitis, associated with synovial cell hyperplasia. Additional changes included chondronecrosis and osteomyelitis. Similar lesions were induced by artificial intravenous inoculation of native colored broilers with the two pathogens. Both species were identified using API Staph kits and detection of 16[Formula: see text]S rRNA genes. Based on a phylogenetic analysis of gap, our isolates of S. cohnii subsp. urealyticum could be divided into two groups. This study is the first report on joint lesions due to S. cohnii subsp. urealyticum infection in broiler chickens.

Total saponins from Discorea nipponica ameliorate urate excretion in hyperuricemic mice.

Rhizoma Dioscoreae Nipponicae, from Discorea nipponica, is a widely used traditional Chinese herb. It is used to treat arthroncus, arthrodynia, and arthritis. Hyperuricemia is an important foundation of gouty arthritis. The current study was aimed at investigating whether the effects of total saponins from Rhizoma Dioscoreae Nipponicae on hyperuricemia were due to renal organic ion transporters in potassium oxonate-induced hyperuricemia mice. Hyperplasia of synovial cells prepared from Wistar rats was induced by IL-1β (1 × 10(4) µg/mL). MTT was used and to screen active components in the inhibition of hyperplasia by total saponins from Rhizoma Dioscoreae Nipponica, individual pure compounds, and different combinations of these compounds. Sixty Kun Ming mice were randomly divided into six groups: normal, model, allopurinol (40 mg/kg), and three total saponins groups receiving dose (600 mg/kg), middle (300 mg/kg), and low doses (60 mg/kg). Hyperuricemic mice were induced with potassium oxonate (300 mg/kg) intragastrically. The total saponins were given six days and the positive drug allopurinol was given one day before inducing hyperuricemia. The serum and urine levels of uric acid and creatinine and the fractional excretion of uric acid were measured in normal and hyperuricemic mice treated with Rhizoma Dioscoreae Nipponicae and allopurinol. The mRNA and protein levels of the mouse urate transporter 1, glucose transporter 9, organic anion transporter 1, and organic anion transporter 3 were analyzed by real-time-PCR and Western blotting methods, respectively. Total saponins from Rhizoma Dioscoreae Nipponicae could effectively reverse potassium oxonate-induced alterations in renal mouse urate transporter 1, glucose transporter 9, organic anion transporter 1, and organic anion transporter 3 mRNA and protein levels, resulting in enhancement of renal urate excretion in mice. These findings suggested that the total saponins from Rhizoma Dioscoreae Nipponicae had a uricosuric effect on the regulation of renal organic ion transporters in hyperuricemic animals.

Four-week toxicity and toxicokinetics of piroxicam and hyaluronic acid combination following intra-articular injection in normal rats

The 4-week toxicity and toxicokinetics of a piroxicam (PX)/ hyaluronic acid (HA) combination were assessed in normal rats after intra-articular (IA) injection into the knee. Rats received PX or HA alone or in combination intra-articularly once a week for 4 weeks at an each dose of 4 mg/kg, a maximum feasible dose. There were transient and reversible changes in food consumption, hematology and serum chemistry, and minimal hypertrophy and hyperplasia of synovial cells on histopathological observation. However, no increase in toxicity was observed with the combination of PX and HA with no dose-dependent manner. Systemic exposure of HA and PX was similar throughout the experimental period when administered alone or concurrently, indicating that there were no pharmacokinetic drug-drug interactions, affecting exposure of either therapeutic agent. This study will support future studies of the IA combination of PX and HA in osteoarthritis-induced animal models and even patients.

A loose screw or two

In May, 2010, a 65-year-old woman presented to our department holding a couple of screws that she had spat out the day before, without any history or recollection of swallowing them. She had no dysphagia or pain. Physical and neurological examinations were normal. She had a 30-year medical history of rheumatoid arthritis, which had resulted in a craniocervical fusion 23 years earlier due to instability of the atlantoaxial segment. On admission, plain radiographs of the cervical spine showed a stable cerclage of the vertebral arches of C1/C2 with normal range of movement in fl exion-extension fi lms (fi gure C). When we compared her radiographs with those taken postoperatively, we were surprised to see additional ventral plating from the clivus to the upper cervical spine (fi gure A). Abdominal radiography and CT showed an osteosynthesis plate and a screw in the right lower abdomen—the missing plate (fi gure D). On laryngoscopy, a small fi brin-coated mucosal dehiscence was detected in the upper pharynx. The edges of the defect were clean, and secondary healing had begun. No further mucosal defects were seen at gastroduoden oscopy. Despite intensifi ed prokinetic therapy, the plate remained stuck in the colon and it was eventually removed by colonoscopy (fi gure B). Our patient was discharged after an uneventful recovery. On follow-up laryngoscopy 3 months later, the mucosal defect of the pharynx had healed completely, and when last seen in August, 2010, she was doing well. Rheumatoid arthritis is a chronic, systemic infl ammatory disorder that aff ects mainly synovial joints. The development of pannus as a secondary hyperplasia of synovial cells, following the infl ammatory response of the synovial joint, leads to progressive destruction of the aff ected joints. At the craniocervical junction, the erosion of the odontoid process of the axis and the transverse ligament leads to atlantoaxial subluxation, which necessitates stabilisation of the aff ected segment, and sometimes resection of the dens axis and craniocervical stabilisation. Loosening of osteosynthesis materials and oesophageal perforations, mainly after surgery of the mid to lower anterior spine have been reported previously. The incidence of this complication is up to 1·49% with an associated mortality rate for oesophageal perforations up to 6% estimated from published data. Predisposing factors are initial malpositioning and subsequent loosening of the screws or plate, or infl ammatory processes around the osteosynthesis. In our patient, infl ammation due to rheumatoid arthritis might be the reason for the delayed loosening and migration of the plate. Perforation of cervical plates and screws into the oesophagus can lead to fi stulas or upper-airway obstruction. The clinical presentation may include coughing, odynophagia or dysphagia, cervical swelling, fever, and subcutaneous emphysema, or asympto matic presentation as in our patient. In patients with chronic infl ammatory disorders, special attention should be given to osteosynthetic joints, because rheumatoid arthritis can lead to loosening and migration of the implants, even after decades. Regular follow-up including radiographs of the aff ected joints is recommended, and special attention has to be given to the occurrence of any of the symptoms mentioned above. In the event of loosening or migration of osteosynthetic materials, a multi-disciplinary approach is recommended.

Resveratrol induces apoptosis MH7A human rheumatoid arthritis synovial cells in a sirtuin 1-dependent manner

Resveratrol, a phytoalexin, reduced the viability of MH7A cells, a human rheumatoid arthritis synovial cell line. In the apoptosis assay, resveratrol increased TUNEL-positive cells and stimulated H2A.X phosphorylation. Resveratrol disrupted mitochondrial membrane potentials in MH7A cells and stimulated cytochrome c release from the mitochondria to the cytosol. Resveratrol activated caspase-3 and caspase-9 but not caspase-8 in MH7A cells. Resveratrol upregulated the expression of the NAD-dependent deacetylase sirtuin 1 mRNA and downregulated the expression of the Bcl-XL mRNA, and resveratrol-induced MH7A cell death, mitochondrial damage, and caspase-3/-9 activation were prevented by sirtinol, an inhibitor of sirtuin 1. The results of the present study show that resveratrol induces MH7A cell apoptosis by activating caspase-9 and the effector caspase-3 along mitochondrial disruption as a result of reduced Bcl-XL expression, allowing cytochrome c release from the mitochondria into the cytosol, in a sirtuin 1-dependent manner. This suggests that resveratrol could suppress hyperplasia of synovial cells, a critical factor of rheumatoid arthritis.

Effects of acupuncture on the number and degranulation ratio of mast cells and expression of tryptase in synovium of rats with adjuvant arthritis

To observe the effects of acupuncture on synovial pathology, synovial mast cell degranulation and tryptase expression and to investigate the relationship between the functions of mast cells and effects of acupuncture on early adjuvant arthritis in rats. Forty-six male Wistar rats were randomly divided into normal control group (n=16), untreated group (n=15) and acupuncture group (n=15). Adjuvant arthritis was induced by injection of 0.1 mL Freund's complete adjuvant in right hind limb footpad. Normal control group and untreated group received no acupuncture treatment, while rats in the acupuncture group were treated with sterilized disposable stainless steel needles inserted perpendicularly as deep as 2 to 3 mm at Xuanzhong (GB39), 6 mm at Shenshu (BL23) and 7 mm at Zusanli (ST36) for eight times (15 min each time) every two days. Setting the modeling day as the 0 day of the experiment, the body weight and paw volume of the rats were measured every three days from the 0 day. In the end, synovial tissues of the right hind ankles were sampled and made into paraffin sections. Then they were firstly stained with hematoxylin-eosin for observing synovial pathology to evaluate the effects of acupuncture on adjuvant arthritis, then stained with toluidine blue for observing the number and degranulation ratio of synovial mast cells and finally detected by immunohistochemical staining method to investigate the expression of tryptase in synovium. Compared with the untreated group, the body weight of rats in the acupuncture group was increased significantly (P<0.05), while the paw volume decreased obviously (P<0.01). Hematoxylin-eosin staining showed that acupuncture significantly inhibited inflammatory cell infiltration, synovial cell hyperplasia, and synovial fibroplasia in synovium of rats with adjuvant arthritis as compared with the untreated group (P<0.05). Toluidine blue staining showed that acupuncture could significantly diminish the numbers of total and degranulated mast cells in rats with adjuvant arthritis (P<0.01), which were significantly higher in the untreated group than in the normal control group (P<0.01). Showing by immunohistochemical staining, the expression of tryptase in synovium in the acupuncture group was decreased as compared with the untreated group (P<0.01). Analyzed by Spearman's bivariate correlation, the number of mast cells and degranulation ratio of mast cells were positively correlated with the pathological scores (r=0.837, P<0.01; r=0.634, P<0.01). Acupuncture can improve pathological condition of inflammatory synovium in rats with early adjuvant arthritis by inhibiting the function of synovial mast cells, which may play an important underlying role in the immunoregulation of acupuncture on adjuvant arthritis.

Recent aspects of the anti-inflammatory actions of glucosamine

Glucosamine, a naturally occurring amino monosaccharide, is present in the connective and cartilage tissues as a component of glycosaminoglycans. Thus, glucosamine has been widely used to treat osteoarthritis, a joint disease characterized by cartilage degeneration, in humans. In addition, glucosamine is expected to exert an anti-inflammatory action, since glucosamine suppresses inflammatory cell activation. To further extend the anti-inflammatory actions of glucosamine, we investigated the effects of glucosamine on synovial cells, endothelial cells and intestinal epithelial cells using in vitro and in vivo systems. Firstly, glucosamine suppressed the IL-1β-induced activation of synovial cells in vitro. Furthermore, glucosamine administration repressed synovial cell hyperplasia, cartilage destruction and inflammatory cell infiltration in rat adjuvant arthritis. Secondary, glucosamine suppressed the TNF-α-induced activation of intestinal epithelial cell HT-29 in vitro. In addition, glucosamine administration improved the clinical symptoms, and colonic inflammation and tissue injury in dextran sulfate sodium-induced colitis in rats. Finally, glucosamine suppressed the TNF-α-induced activation of endothelial cells in vitro. Moreover, glucosamine administration repressed the formation of atherosclerotic lesion and infiltration of inflammatory cells into the lesion in spontaneously hyperlipidemic mice B6 KOR Apo shl. Together these observations support the idea that glucosamine can function as not only a chondroprotective agent but also an anti-inflammatory molecule in the body.

Involvement of thioredoxin reductase 1 in the regulation of redox balance and viability of rheumatoid synovial cells

Rheumatoid arthritis (RA), a chronic and systemic disease of unknown etiology, is characterized by hyperplasia of synovial cells, which ultimately lead to the destruction of cartilage and bone. To elucidate the molecular mechanisms that lead to RA, we analyzed synovial cells established from patients with RA by oligonucleotide microarrays. Gene expression profiles clearly suggested that oxidative stress is enhanced in RA synovial cells, which was confirmed by measuring cellular levels of reactive oxygen species. One of the highly up-regulated proteins in RA synovial cells was thioredoxin reductase 1 (TRXR1), a protein that plays an important role in antioxidant defense system. Subsequent analysis demonstrated that TRXR1 suppresses hydrogen peroxide and inhibits apoptosis of RA synovial cells. Thus, our results reveal a novel pathophysiologic function of RA synovial cells as a generator of oxidative stress, and a self-defense mechanism against self-generated oxidative stress.

Concurrent gene therapy strategies effectively destroy synoviocytes of patients with rheumatoid arthritis

Objectives. Rheumatoid arthritis (RA) is characterized by the chronic inflammation of the synovial joints resulting from the hyperplasia of synovial cells and the infiltration of lymphocytes, macrophages and plasma cells. Currently, the aetiology of RA is not known, and new treatment modalities are needed to prevent the disease progression. Apoptosis induction of synovial cells through the use of death ligands has been explored as a treatment modality for RA. Thus, the primary objective of this study was the testing of the efficacy of adenovirus delivery of human TRAIL (Ad5hTRAIL) for the treatment of patients with RA. Methods. Primary synovial cell cultures were established from eight patients with RA. Adenovirus permissiveness of synovial cells was determined by the infection of synoviocytes with adenovirus vector encoding green fluorescent protein (AdEGFP). TRAIL sensitivity of synoviocytes was assessed through the infection with Ad5hTRAIL vector using Live/Death Cellular Viability/Toxicity kit from Molecular Probe. TRAIL receptor profiles of synoviocytes were revealed by real-time RT-PCR assays followed by flow cytometric analyses. Results. While the presence of TRAIL death receptors were necessary for the induction of cell death, high levels of TRAIL-R4 decoy receptor expression on surface were correlated with TRAIL resistance. A DcR2 siRNA approach in combination with Ad5hTRAIL infection eliminated apoptosis-resistant RA synovial fibroblasts. Conclusion. Because a DcR2 siRNA approach in combination with Ad5hTRAIL infection exterminated RA synoviocytes to a greater extent than Ad5hTRAIL alone, the modulation of TRAIL receptor expression might be a new gene therapy strategy to sensitize RA synoviocytes to TRAIL.